Polyarylene sulfides are high-performance polymers that may withstand high thermal, chemical, and mechanical stresses and are beneficially utilized in a wide variety of applications. Polyarylene sulfides are generally formed via polymerization of a dihaloaromatic monomer with an alkali metal sulfide or an alkali metal hydrosulfide in an organic amide solvent, forming polymers that include halogen at the termini.
A desire for low halogen content polymers has developed over the last several years. For instance, sulfur-containing polymers with low organically-bound chlorine content are useful in electrical and computer applications. Moreover, the environmental impact of halogens has prompted many industries to examine raw materials with lower halogen content. Attempts have been made to produce low halogen-content sulfur-containing polymers. For instance, higher molecular weight polymers, which have fewer terminal groups and hence lower halogen content, have been used in low halogen applications. Unfortunately, high molecular weight polymers have high melt viscosity, leading to processability problems. Other attempts have included the use of more costly raw materials and chemically removing halogens following formation by use of reducing/nucleophilic reagents, which adds processing steps and costs to the formation process.
What is needed in the art is a method for formation of low halogen content sulfur containing polymers. For instance, methods for the formation of low halogen content sulfur containing polymers having a low melt viscosity and good processability would be of great benefit.